warpdb
DSL-driven RDBMS interface for Java:
Status:
Design principles
- JPA-annotation based configuration.
- DSL-style API reads like English.
- Support raw SQL for very complex query.
- No "attach/dettach".
- All entities are simple POJOs without proxy-ing.
Database Support
- MySQL 5.x
Configuration
Maven dependency:
<dependency>
<groupId>com.itranswarp</groupId>
<artifactId>warpdb</artifactId>
<version>5.0.4</version>
</dependency>
Warpdb is built on top of Spring-JDBC. JdbcTemplate or DataSource is required when build warpdb instance:
<bean class="com.itranswarp.warpdb.WarpDb" init-method="init">
<property name="basePackages">
<list>
<value>com.test.product.model</value>
<value>com.test.order.model</value>
</list>
</property>
<property name="jdbcTemplate" ref="jdbcTemplate" />
</bean>
Or using data source:
<bean class="com.itranswarp.warpdb.WarpDb" init-method="init">
<property name="basePackages">
<list>
<value>com.test.product.model</value>
<value>com.test.order.model</value>
</list>
</property>
<property name="dataSource" ref="dataSource" />
</bean>
Basic Usage
Fully JPA Annotation Support
Entities are configured with JPA annotation:
@Entity
@Table(name="user")
public class User {
@Id
String id;
@Column(nullable=false)
String name;
}
Query
Query by primary key:
// get user, or throw EntityNotFoundException if not found:
User user = warpdb.get(User.class, "123");
// get user, or return null if not found:
User another = warpdb.fetch(User.class, "456");
You have to provide multiple values if multiple id columns are defined:
Product p = warpdb.get(Product.class, "p123", "c456);
Warpdb supports criteria query and raw SQL query, both are type-safe:
List<User> users = warpdb.from(User.class)
.where("name=?", "bob")
.orderBy("updatedAt").desc()
.list();
Get first result or null if not found:
User user = warpdb.from(User.class)
.where("name=?", "bob")
.orderBy("updatedAt").desc()
.first();
Query for update:
User user = warpdb.selectForUpdate()
.where("id=?", 123)
.first();
Using raw SQL:
List<User> users = warpdb.query("select * from User order by name limit 100");
Paged Query
Warpdb supports paged query by specify page index and page size:
// page 3, 10 items per page:
PagedResults<User> pr = warpdb.from(User.class)
.orderBy("updatedAt")
.list(3, 10);
System.out.println(pr.page.pageIndex); // 3
System.out.println(pr.page.itemsPerPage); // 10
System.out.println(pr.page.totalPages); // 92
System.out.println(pr.page.totalItems); // 912
List<User> list = pr.results; // current page items
A paged query will generate 2 SQLs when execute list(pageIndex, pageSize):
SELECT COUNT(*) FROM User;
SELECT * FROM User ORDER BY updatedAt limit 20, 10
Insert
Using insert() to insert one or more entities:
User user = new User();
user.setId(...);
user.setName(...);
Product product = new Product();
product.setId(...);
product.setName(...);
warpdb.insert(user, product);
Batch insert
Using insert(List<T>) to do batch save entities.
Update
Using update() to update one or more entities:
User user = ...
user.setName(...);
Product product = ...
product.setName(...);
warpdb.update(user, product);
Batch update
Using update(List<T>) to do batch update entities.
Remove
Using remove() to remove one or more entities:
User user = ...
Product product = ...
warpdb.remove(user, product);
Batch remove
Using remove(List<T>) to do batch remove entities.
Misc
Enum Support
Enum is stored as VARCHAR(50) in database:
@Entity
public class User {
RoleEnum role;
}
Attribute Converter
Values used in Java and db can be converted by attribute converter:
@Entity
public class User {
// stored as "DATE" in db:
@Convert(converter = LocalDateConverter.class)
@Column(columnDefinition = "date")
public LocalDate birth;
}
Listeners
Listeners must be added as entity method with annotation PostLoad, PrePersist, PostPersist, PreUpdate, PostUpdate, PreRemove, PostRemove:
@Entity
public class User {
@Id
String id;
long createdAt;
@PrePersist()
public void prePersist() {
if (this.id == null) {
this.id = nextId();
}
this.createdAt = System.currentTimeMillis();
}
}
Schema Export
Using getDDL() to export schema:
String ddl = warpdb.getDDL();
or get schema for one entity:
String ddl = warpdb.getDDL(User.class);